BBC Planet Earth
I've been watching the lovely documentaries on this 5 disc DVD special, and there is some really beautiful photography and lots of information on the arctic. They cover the emperor penguins in the antarctic as well, and have some interesting footage that you wouldn't have seen in March of the Penguins.
I haven't seen Arctic Tale yet, but this BBC series has some great footage of a polar bear who swims 60 miles a day for days on end searching for food, and then when he reaches a group of walruses he's too exhausted to kill one. The ice is melting, and that's not propaganda -- it's fact. The BBC production doesn't 'cutesify' the bears or walruses, it just shows them as they are, and there are no judgments about the cause of global warming. If you're afraid of having a liberal agenda 'shoved down' your throat, then you might want to consider watching this version instead. The photography truly is stunning.